NovaException: Unexpected vif_type=binding_failed - Openstack

Some time you may face and error
"NovaException: Unexpected vif_type=binding_failed" 
in the compute log of nova compute node while trying to deploy a virtual machine. The detailed log is looks like below.

INFRASTRUCTURE
Centos 6.5 in All the nodes with Kernel 2.6.32-504.1.3 (64B)
Centos 6.5 in Compute node with Kernel 3.18.1 (64B). RBD module is not loaded automatically in 2.6.2, thats why i am using 3.18.1 in Compute node.
Openstack Icehouse.

TRACE nova.compute.manager [instance: 84ff8ab0-7bc1-41ac-b7a7-d5a86fceaa0e] NovaException: Unexpected vif_type=binding_failed

This is normally happens because of a wrong configuration parameter in the Layer2 plugin configuration in the Neutron node and Compute node. You can change it like below.

Edit /etc/neutron/plugins/ml2/ml2_conf.ini  on both compute and network node

Change ‘tunnel_type = gre’ to ‘tunnel_types = gre’

And Restart the services.

COMPUTE NODE

service openvswitch  restart

service neutron-openvswitch-agent restart

NEUTRON NODE

service neutron-openvswitch-agent restart

service neutron-l3-agent restart

service neutron-dhcp-agent restart

service neutron-metadata-agent restart

Everything will be fine after this.